The Slave Trade to the Río de la Plata, 1777–1812: Trans-Imperial Networks and Atlantic Warfare

Atlantic European empires faced reform and centralization in the second half of the eighteenth century at a time when Spanish American dominions were challenged by British and Portuguese interests. The Seven Years War (1756 1763) left an important part of Spanish America confronting the British possessions of North America and the West Indies and the Portuguese in the Rio de la Plata. The periphery of the Spanish Empire*Cuba, Venezuela, and the Rio de la Plata*experienced both Atlantic warfare and economic growth as Spain turned to a more commercial and maritime model of Atlantic empire (Elliot 2006, 292 324). This era of imperial redefinition coincided with the zenith of the transatlantic slave trade. From a total of twelve and a half million enslaved Africans who crossed the Atlantic between 1500 and 1867, almost six million made this passage between 1750 and 1825 (Behrendt et al.). Sharp imperial competition developed in the Atlantic over the production of staples, shipping, and the acquisition of slave labor. However, as this study will show, instead of rivalry it was actually trading cooperation between the Spanish and the Portuguese in the South Atlantic that led to the introduction of the greatest number of enslaved Africans in the history of the Rio de la Plata. This study provides a revised quantification of the slaves entering in the Viceroyalty of the Rio de la Plata. By studying the slave trading connections of this region with both Brazil and Africa, this article shows how Luso-Spanish networks shaped the slave routes ending in Buenos Aires and Montevideo. The trans-imperial networks which drove this southernmost branch of the slave trade might seem inimical to the mercantilist policies held by the Spanish and Portuguese metropolis, but they continued as this traffic benefited specific aspects of imperial trade and expansion. While illegal for the Portuguese Crown, the slave trade from both Brazil and Mozambique to the Rio de la Plata provided a continuous inflow of silver*the blood of Portuguese commerce in Asia and a source of specie for the empire.